Just read Bill Burnham's post about Persistent Search - this stuff is already available via Yahoo! APIs. Simply combine our Search RSS feeds with our Feed Alert system and you can get an IM, Email or an SMS (in the US) when the search changes. After spending some quality time with the APIs this weekend, it was pretty easy to whip up a demo:

Persistant Web Search:

That took me a couple minutes only because I wanted to make it one click so I used some javascript. You can persist image, audio, news, blog and other searches as well if you want as well with a few tweaks. Check out all the Search APIs here over the developer.yahoo.net site.

-Russ

Woops - the javascript was broken. I had to double-escape the search term for multiple words. It should be working now. Also, I should've explained more clearly the APIs I was using.

First the search feed URL (which you have to escape):
* http://api.search.yahoo.com/WebSearchService/rss/webSearch.xml?appid=yahoosearchwebrss&query=My+Search+Term
and the URL to add the feed to your alerts:
* http://alerts.yahoo.com/main.php?view=blogs&url=http://www.example.com/feed